Brazilian federal police are targeting Senator Ciro Nogueira, a powerful ally of former President Jair Bolsonaro, as part of an expanding probe into the failed Banco Master, Bloomberg reported Thursday.

Authorities are carrying out search and seizure warrants against Nogueira and others in a new phase of the investigation, the Federal Police said in a statement cited by Bloomberg. According to a Supreme Court document authorizing Thursday’s operation, police pointed to “undue advantages” tied to Nogueira’s relationship with former Master chief executive Daniel Vorcaro, including recurring payments from the banker to the senator.

Police say they have identified recurring monthly payments from Vorcaro to Nogueira that started at 300,000 reais (about $61,000) and later rose to 500,000 reais. The document also cited the loan of a high-end property and payments for international travel, accommodation, restaurants and private flights, according to Bloomberg.

Investigators also allege that Nogueira acquired a stake in Green Investimentos SA estimated at 13 million reais for just 1 million reais. The sale of a 30 percent stake was made to CNLF Empreendimentos Imobiliários Ltda, a company managed by the senator’s brother, according to the news outlet.

Police separately believe that a 2024 congressional amendment introduced by Nogueira to expand deposit insurance coverage to 1 million reais from 250,000 reais was drafted by Banco Master’s staff. Vorcaro then allegedly sent the draft, which became known as the “Master amendment,” to the senator’s residence, the news outlet said. The amendment was never approved.

The action against Nogueira marks the latest turn in a saga that has rattled Brazilian politics since the central bank liquidated Banco Master in November amid fraud accusations. The scandal has reached from Congress to the Supreme Court because of Vorcaro’s apparent ties to officials in positions of power, according to the report

Nogueira, who served as Bolsonaro’s chief of staff, is among the leaders of the Centrão, an influential bloc of centrist lawmakers that wields significant power in the legislature, Bloomberg reported. Vorcaro, who has been arrested twice in the fraud probe, described Nogueira as “a great friend” in text messages disclosed in an earlier stage of the investigation.

“The police narrative emphasizes that the evidence collected points to the existence of a functional and instrumental arrangement guided by mutual benefit, going beyond mere friendship,” Justice André Mendonça, who is overseeing the Banco Master investigation, said in the document cited in the report.